Unfortunately, AWN continues to depend on valac-0.12 which is obsolete, meaning that AWN won't make it in the official Ubuntu / Debian repositories unless it's ported to a newer valac version. However, you can install it in Ubuntu 13.10 by using the AWN Testing PPA (for Ubuntu 13.04 or 12.10 you can use the main WebUpd8 PPA; AWN is available in the official Ubuntu 12.04 repositories).

Install Avant Window Navigator in Ubuntu

To add the AWN testing PPA and install Avant Window Navigator in Ubuntu 13.10, use the following commands: